Lipoamide is a trivial name for 6,8-dithiooctanoic amides and a form in which 6,8-dithiooctanoic acid is bound to protein via an amide bond of its carboxyl group with the amino group of lysine. Lipoamides can transfer acetaldehyde group to CoA to continue the TCA cycle. α-lipoic acid has been researched for preventing various diseases related to oxidative obstacle to mitochondrial functions. It has been known that lipoamides play a role of cofactor to an enzyme of α-oxo-acid dehydrogenase, stimulate recovery from myocardial infarction, and have physiological characteristics effectively to prevent cell necrosis with a role of antioxidant.
Polysaccharides such as chondroitin sulfates and hyaluronic acids which are used with the lipoamide in the present disclosure are biological compounds fermented by microorganisms or extracted from animals and have free carboxyl groups in their molecules. They are multilaterally used in the industrial fields of medical engineering, biocompatible materials, chemistry, medical science, biotechnology, and cosmetics. They are employed as materials for drug or cell delivery carriers, medicines for curing arthritis, and scaffolds for tissue engineering such as artificial cartilages, and the likes in medical science and engineering, and moisturizers in cosmetics.
To date, no biocompatible polymers using both lipoamide and chondroitin sulfate for tissue engineering have been reported. Known patents and patent applications related to lipoamide are “composition for diagnosis of liver cell cancer, liver cell cancer diagnosis kit including the same, and liver cell cancer diagnosis method”, “method for sterilizing albumin-inclusive formulations”, “pharmaceutical composition including hydroxymic acid derivatives”, and “sterilization method of biological components”, though they fail to suggest what this disclosure provides for.
Acknowledged patent documents related to the polysaccharide compounds of hyaluronic acid and chondroitin sulfate are “biodecomposable thermal-sensitive polyphosphazene hydrogel, its preparation method and its use”, “tissue engineering implant for nerve regeneration using biocompatible injection hydrogel”, “composition and method for restoration and regeneration of cartilage and other tissues”, “composition for liver cell cancer diagnosis, liver cell cancer diagnosis kit including the same, and liver cell cancer diagnosis method”, “liquid and method for preventing tissue adhesion”, and “method for curing hair and nail using alkanolamine”. Recently, there have been reported studies on the various excellent biological characteristics of chondroitin sulfate and hyaluronic acid such as stanching function (oligosaccharide's property for prevention of blood coagulation), bioactive material delivery carrier (the characteristic of hydrogel material and drug delivery system as a binding of DNA-chondroitin sulfate and hyaluronic acid), and scaffold for tissue engineering to show the possibility of its application as biocompatible materials.
Carboxymethyl cellulose is a kind of nontoxic polysaccharide compound, in which the alcohol group of glucopyranose monomer consisting of the skeleton of cellulose is substituted with carboxymethyl group. It does not cause an allergy reaction and is used as biocompatible material for medical appliances such as antiadhesion agent due to its excellent biocompatibility. It is also used as eye drops agent, food material, paste material and viscosity enhancer by adjusting its properties in its high viscosity and leading to the bond of carboxymethyl group. Acknowledged patents related to carboxymethyl cellulose are “carboxymethyl cellulose binder and lithium battery employing the same”, “biodecomposable pharmaceutical composition and particulate formulation which enable human growth hormone continuously to be released”, “mucous membrane adhesive inotophoresis device”, “opthalmological liquid including sodium carboxymethyl cellulose and hydroxypropylmethyl cellulose”, “bioabsorbable composition of carboxy polysaccharide polyether interpolymer complex and method for using the same for decreasing surgical operational adhesion”, “composition for bone filling to promote osteogenesis and early bone hardening”, and “method for preparing amphiphilic heparin derivative to increase absorption at the mucous membrane”, as they prove the medical usability of carboxymethyl cellulose.
Acknowledged patents related to heparin are “multifunctional amphiphilic copolymer and method for preparation of the same”, “method for preparing amphiphilic heparin derivative to increase absorption at the mucous membrane”, “bioactive material fixed artificial blood vessel”, and “angiogenesis heparin bound peptide amphiphilic compound”, although there are none patented to use heparin and lipoamide together.
Studies on industrial application of a product in the bound form of the lipoamide and polysaccharide compounds have not been active in spite of the biological excellence of the respective lipoamide and polysaccharide compounds. Therefore, the present disclosure has been completed in an effort to make lipoamide derivatives, hydrogel and film using the same to exhibit the biological functions of polysaccharide compounds to the maximum by means of binding the carboxy group in chondroitin sulfate, carboxymethyl cellulose, heparin and hyaluronic acid with the lipoamide, in order to fulfill the need to develop highly functional/high value added materials (for example, medicine materials) by making use of lipoamide which leads commercially to chondroitin sulfate, heparin, carboxymethyl cellulose and hyaluronic acid derivatives.